YOU’LL NEED THIS

PODMAN You can install this natively in Linux or through WSL in Windows. For a beginner’s guide to Podman, see the February 2024 issue.

1 PREPARATORY STEPS

Whether installing Podman alongside an existing installation of Docker, or setting it up for the first time on a new machine, the first thing you need to do is migrate your existing container data across to Podman. We recommend storing everything inside a parent container data folder (container-data or podman-container-data, if Docker is already present) in an accessible location. This might be inside C:\Users\ Username in Windows, or your home (~) folder in Linux. You then create individual subfolders for each container inside this.

» Because Podman runs rootless by default under your own username, you’ll need to ensure that all your container folders are accessible. Permission issues don’t exist for Windows users because of the way both Docker and Podman run within the Windows Subsystem for Linux, but if you’re running a native Linux install like Debian or Ubuntu Server, you’ll need to take ownership of the entire container-data folder. Input the following command, substituting username:username with your own Linux username, such as nick:nick): sudo chown -R username:username ~/container-data

» Now, verify that the permissions have been updated: cd ~/container-data && ls -l

» If all is as it should be, your username should be listed as the owner of all the sub-folders, as shown in [Image A].

A COUPLE OF ISSUES AGO, we introduced you to a new, more secure way of running containerized apps on your PC: Podman. However, while Podman is designed to work with Docker containers, the way it functions means they’re not 100 percent compatible—at least in their native form. That’s down to two primary reasons: the first is that Podman runs under your own user account to provide containers with ‘rootless’ access to your system, and the second is that containers are set up to run independently instead of through an additional Docker daemon process.

Rootless access prevents containers from being given the keys to your system, but can cause problems for those that need elevated access in certain areas. The lack of a parent daemon also requires a different approach to configuring containers to auto-start with your system. In this tutorial, we’ll examine these key differences and explain ways in which you can circumvent them to get a selection of popular containers. You’ll also equip yourself with the know-how to get other containers working. We’ve focused on the Linux implementation of Podman, but you can easily tweak these instructions to work with Podman in Windows, too. –NICK PEERS